In situ TEM observations of room temperature dislocation climb at interfaces in nanolayered Al/Nb composites

Li, Nan; Wang, Jian; Huang, Jianyu; Misra, Amit; Zhang, X.

doi:10.1016/j.scriptamat.2010.04.005

Cited by 87 publications

(47 citation statements)

References 32 publications

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“…36,37 MD simulations indicate a high formation energy for single vacancy,~2.45 eV, as one Cu or Al atom is removed. Such high vacancy formation energy does not favor climb at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Dislocations interaction induced structural instability in intermetallic Al2Cu

et al. 2017

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Intermetallic precipitates are widely used to tailor mechanical properties of structural alloys but are often destabilized during plastic deformation. Using atomistic simulations, we elucidate structural instability mechanisms of intermetallic precipitates associated with dislocation motion in a model system of Al 2 Cu. Interaction of non-coplanar <001> dislocation dipoles during plastic deformation results in anomalous reactions-the creation of vacancies accompanied with climb and collective glide of <001> dislocation associated with the dislocation core change and atomic shuffle-accounting for structural instability in intermetallic Al 2 Cu. This process is profound with decreasing separation of non-coplanar dislocations and increasing temperature and is likely to be operative in other non-cubic intermetallic compounds as well.

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Section: Resultsmentioning

confidence: 99%

Dislocations interaction induced structural instability in intermetallic Al2Cu

et al. 2017

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“…Interfaces act as strong barriers for confining dislocation propagation within layers [1][2][3][4][5][6][7] and transmitting lattice dislocation across interfaces [8][9][10][11][12][13]. As the interface spacing decreases to a few nanometers, experimental characterization using in situ and ex situ transmission electron microscopy [14][15][16][17][18] indicate that lattice dislocations are likely trapped in the interfaces [4,14]. In addition, the stress required for lattice dislocations propagation within layers significantly increases with decreasing layer thickness [19].…”

Section: Introductionmentioning

confidence: 99%

Glide dislocation nucleation from dislocation nodes at semi-coherent {1 1 1} Cu–Ni interfaces

et al. 2015

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a b s t r a c tUsing atomistic simulations and dislocation theory on a model system of semi-coherent {1 1 1} interfaces, it is shown that misfit dislocation nodes adopt multiple atomic arrangements corresponding to the creation and redistribution of excess volume at the nodes. Four distinctive node structures were identified: volume-smeared nodes with (i) spiral or (ii) straight dislocation patterns, and volume-condensed nodes with (iii) triangular or (iv) hexagonal dislocation patterns. Volume-smeared nodes contain interfacial dislocations lying in the Cu-Ni interface but volume-condensed nodes contain two sets of interfacial dislocations in the two adjacent interfaces and jogs across the atomic layer between the two adjacent interfaces. Under biaxial tension/compression applied parallel to the interface, it is shown that the nucleation of lattice dislocations is preferred at the nodes and is correlated with the reduction of excess volume at the nodes.

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“…In addition, the anisotropic kinetics in association with the climb process could correlate with the difference in the flow stress between twinning and de-twinning in hcp metals during cyclic loading [32]. Further experimental evidence is required, particularly, in situ high-resolution transmission electron microscopy observations in single crystals that can provide insights into kinetic processes at the atomic scale [33,34] and/or in situ measurements of the critical stresses and velocities in association with the migration of twin boundaries during twinning and detwinning in single crystals by using transmission electron microscopy that can provide insights into understanding the anisotropic kinetics and the twinning-associated hardening at meso scale [35][36][37][38].…”

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confidence: 99%